Module org.apache.jena.arq

Package org.apache.jena.sparql.core

Class DatasetGraphFactory

java.lang.Object

org.apache.jena.sparql.core.DatasetGraphFactory

public class DatasetGraphFactory
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	DatasetGraphFactory.GraphMaker	Interface for making graphs when a dataset needs to add a new graph.

Field Summary

Fields

Modifier and Type	Field	Description
static DatasetGraphFactory.GraphMaker	graphMakerMem	A graph maker that creates unnamed Jena default graphs
static DatasetGraphFactory.GraphMaker	graphMakerNamedGraphMem	A graph maker that creates NamedGraphs around a Jena default graphs
static DatasetGraphFactory.GraphMaker	graphMakerNull	A graph maker that doesn't make graphs.

Constructor Summary

Constructors

Constructor	Description
DatasetGraphFactory()

Method Summary

Modifier and Type	Method	Description
static DatasetGraph	cloneStructure(DatasetGraph dsg)	Clone the structure of a DatasetGraph.
static DatasetGraph	create()	Create an in-memory Dataset.
static DatasetGraph	create(Graph dftGraph)	Create a DatasetGraph starting with a single graph.
static DatasetGraph	createGeneral()	Create a general-purpose Dataset. Any graphs needed are in-memory unless explicitly added with Dataset.addNamedModel(java.lang.String, org.apache.jena.rdf.model.Model).
static DatasetGraph	createTxnMem()	Create an in-memory, transactional Dataset.
static DatasetGraph	empty()	An always empty DatasetGraph.
static DatasetGraph	wrap(Graph graph)	Create a DatasetGraph which only ever has a single default graph.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

graphMakerNull

public static DatasetGraphFactory.GraphMaker graphMakerNull

A graph maker that doesn't make graphs.

graphMakerMem

public static DatasetGraphFactory.GraphMaker graphMakerMem

A graph maker that creates unnamed Jena default graphs

graphMakerNamedGraphMem

public static DatasetGraphFactory.GraphMaker graphMakerNamedGraphMem

A graph maker that creates NamedGraphs around a Jena default graphs

Constructor Details

DatasetGraphFactory

public DatasetGraphFactory()

Method Details

create

public static DatasetGraph create()

Create an in-memory Dataset.

See also createTxnMem() for a transactional dataset.

This implementation copies models when Dataset.addNamedModel(String, Model) is called.

This implementation provides "best effort" transactions; it only provides MRSW locking. Use createTxnMem() for a proper in-memory transactional DatasetGraph.

See Also:

• createTxnMem()

createTxnMem

public static DatasetGraph createTxnMem()

Create an in-memory, transactional Dataset.

This fully supports transactions, including abort to roll-back changes. It provides "autocommit" if operations are performed outside a transaction but with a performance impact (the implementation adds a begin/commit around each add or delete so overheads can accumulate).

Returns:

a transactional, in-memory, modifiable DatasetGraph

createGeneral

public static DatasetGraph createGeneral()

Create a general-purpose Dataset.
Any graphs needed are in-memory unless explicitly added with Dataset.addNamedModel(java.lang.String, org.apache.jena.rdf.model.Model).

This dataset type can contain graphs from any source when added via Dataset.addNamedModel(java.lang.String, org.apache.jena.rdf.model.Model). These are held as links to the supplied graph and not copied.

This dataset does not support the graph indexing feature of jena-text.

This dataset does not support serialized transactions (it only provides MRSW locking).

Returns:

a general-purpose Dataset

See Also:

• createTxnMem()

cloneStructure

public static DatasetGraph cloneStructure(DatasetGraph dsg)

Clone the structure of a DatasetGraph.

create

public static DatasetGraph create(Graph dftGraph)

Create a DatasetGraph starting with a single graph. New graphs must be explicitly added.

wrap

public static DatasetGraph wrap(Graph graph)

Create a DatasetGraph which only ever has a single default graph.

empty

public static DatasetGraph empty()

An always empty DatasetGraph. It has one graph (the default graph) with zero triples. No changes allowed - this is not a sink.